Lifting-jack.



ff. fjomTED sTATEs raars f' y lFnEImRIoK F. Messina, or Mantente HAT,ALBERTA, CANADA.

' LlFTING-JACK.

To all 'whom it 'may concern:

Be itknown ythat I, FREDERICK F. Md BRIDE, a citizen of the Dominion ofCanada7 residing at Medicine Hat, in the Province of Alberta andDominion of Canada, have invented new and useful Improvements inLifting-Jacks, vof which the following is a specification. f

This invention relates to new and usetu improvements in lifting jacksand the pr1ncipal object of the invention is to provide a yoke orengaging member embracing a screw-threaded standard and carrying a litting ring having screwlthreaded engagement with the standard androtatably mounted Within the yoke with means carried by the yoke forrotating the ring.

Another object of the invention is to provide a ball bearing arrangementbetween" the ring and yoke and to rotate the ring by worm gearing.

Another object of the invention is to provide a device of this characterwhich is simple and durable in construction, reliable and eiiicient inoperation and one which can be manufactured and placed upon the marketat a minimum cost.

The invention also consists in certain other features of constructionand in the combination and arrangement of the several parts, to behereinafter fully described, illustrated in the accompanying drawingsand specifically pointed out in the appended claim. Y In describing myinvention in detail, ref- .erence will beA had to the accompanyingdrawings wherein like characters denote like or corresponding partsthroughout the sev? eral views, and in whichz Figure l is an elevationof the device.

Fig. 2 is a vertical section.

Fig. 3 is a cross section on line 3-3 of Fig. l. Y

Fig. 4 is a detail showing the wirestretchers.

As shown in these figures l represents the standard provided withscrew-threads and being secured to a base 2 at one end and having a head3 at the other end. 4 represents. the yoke which embraces the standardand which is provided withla nose 5 and a recess V6. 7 indicates a `ringlocated in said recess and provided with' interior screw- Specication ofLetters Patent.

Patented Nov. 26, 191 8.

Serial No. 216,338.

threads engaging with the threads on the standard. Qn its outerperiphery said ring is provided with the worm-teeth 8 which cngage withthe worm 9 carried by the voke and rotated by the crank l0. 1l indicatesa ring loosely embracing the standard and located in the recess in theyoke, said ring being located above the ring 7 and ball bearings l'2`arelocated between said rings. The ring ll hears against the upper surfaceot the recess.

It will thus be seen that when the crank is turned to rotate the worm 9that the ring 7 will also be rotated so that thc same will travel on thestandard and by reason ot' the fact that it is connected with the yokethe said yoke will be caused to travel along with the ring. In this wayby placing the nose 5 of the yoke under an object to be lifted thc samecan be easily raised by rotating the crank 10.

`While I have described the invention as a lifting jack it will otcourse be understood that the jack may be used for other purposes. Forinstance it may be used as a Wirefstretchcr by placing the semi-circularmembers A at opposite sides ot' the head 3 and pivoting the members B tosaid head at the points B, said members having the curved ends BX forcooperating with they members A to grip the strands ot' wire betweenthem., as shown in detail in Fig. et. The wire holding means justdescribed are also placed on the yoke and in using the device the base 2is suitably secured to a post and the stretchers carried by the yokeconnected with the wires, the yoke being irst run up to the top of thestandard,fthen by running the yoke toward the base the wires will bestretched. The wires are then gripped by the devices carried by the headso as *to hold the said wires against movement and then the yoke is runback to the head and a new hold taken and so on until the wires aresufficiently stretched. It will be understood that in this operation thestandard extends horizontally.

It is thought from. the foregoing description that the advantages andnovel features of my invention will be readily apparent.

I desire. it to be understood that bI may make slight changes in theconstruction and in 'the combination and zu'iailgeiiiefiig ofthe yoke, acrank for rotating the worm, worm 14'0 several pzue, provided that suchchanges teeth on the outer periphery of the ring enfall within the scopeof the appended claim. gnging with said Worm, a second ring em- W'hzit Iclaim is bracing the standard and located Within the A lifting jackcomprising; a screw-thread recess, and ball bearings located between ed5 andzu'd, :i yoke loosely embracing che Said rings. e same uid having arecess therein-` a. screw In testimony Whereofl affix my signatiire.threndel ring cnmlging lle standard and sented in\qid iec: es, :i worincarried by the FREDERICK F. MCBRIDE;

